Tor Browser (TB) is a modified version of Mozilla's Firefox Extended
Service Release customized for web browsing over the Tor anonymity
network. In addition to obscuring the client's IP address, TB also
mitigates browser fingerprinting attacks and patches the Mozilla code
in other ways to prevent privacy leaks.

Tor Browser includes the patched version of Firefox ESR and four
Firefox add-ons:

* torbutton: an add-on from the Tor project that provides a configuration
  GUI in the browser (the onion button);
* tor-launcher: another add-on from the Tor project that allows Tor
  Browser to control and interface with a private instance of the tor
  daemon used by Tor Browser;
* noscript: a well-known add-on for Firefox that allows flexible blocking
  of JS.  The version in the Tor Browser ports is specifically configured
  for use in Tor Browser by the Tor project and is not for use with other
  Mozilla-based browsers;
* https-everywhere: an add-on for Firefox from EFF that attempts to turn
  http:// requests into https:// requests wherever possible.  Like noscript,
  the verison in the Tor Browser ports is specifically configured for use
  in Tor Browser.
